Switch-contact finger



Sept. 9 1924. 1,508,191

G.LEDmCK SWITCH CONTACT FINGER Filed Dec. 16. 1920 InvenBor:

GeOrgeLeddicR,

195 Hisjqttorngy.

Patented Sept. 9, 1924.

UNITED STATES 15mm PATENT OFFICE.

GEORGE LEDDICK, OF S OHENECTADY, NEW YORK, A$SIGNOR T0 GENERAL EIIECTRIO COMPANY, A CORPORATION OF NEW YORK.

SWITCH-CONTACT FINGER.

Application filed December 16, 1920. Serial No. 431,090.

To all whom it may concern.

Be it known that I, GEORGE LEDDIOK, a citizen of the United States, residing at Schenectady, in the county of Schenectady, State of NeW York, have invented certain new and useful Improvements in Switch- Contact Fingers, of which the following is a specification. I

My invention relates to improvements in contact fingers for electric switches. The invention is particularly directed to improve ments in the wiping type of contact fingers; that .is, a type of'finger which is adapted to make wiping or sliding engagement with another switch contact.

One of the objects of the inventionis to provide a finger of the type indicated which shall have a minimum. of parts, which shall be simple in construction, which can be cheaply manufactured, and which will nevertheless be effective and durable in operation.

Another object of the invention is to provide an improved contact finger in which the part or parts which become worn in service can be easily and quickly replaced.

For an understanding of the nature of the invention and its advantages, reference is had to the accompanying. drawing, in which Fig. 1 is a perspective view of my improved 1) surface .of the contact 16 brought into encontact finger,.and Fig. 2 is a cross-section of the same on the long axis of the finger.

The contact finger comprises a support 10, a contact member 11, and a resiliently mounted strap 12 adapted to embrace the support and member to hold the member in engagement with the support and permitthe member to have a limited angular movement with respect to the support. The'suppo'rt carries on one end a stop 13 on which the contact member 11 is adapted to rest, and theother end of the support is adapted to be secured to some rigid part of the switch mechanism (not shown). The stop 13 is. interposed between the ends of the contact member, and the strap 12 .is disposed between this stop and the right hand end 14 of the member. The end 14 of the member carries a .pin 15 which 1s adapted to enter an aperture in the support 10 to form an open pivot connection about which the member is permitted'a limited angular movement. The other end of the contact member carries a contact 16 which is adaptedto make engagement with another switch contact member (not shown) in order to complete the electric circuit. Strap 12 is preferably formed of a single narrow strip of metal with an integral punched-in portion 19 midway of the ends of the strap for holding the spring 18 in position, and integral kicked up ends 17 which practically meet on the side of the support opposite to the side on which the contact member, the spring and the major portion of the. strap are carried. These integral projecting ends are arranged-to enter an aperture in the said opposite side of the support for positioning the strap with respect to the support. The spring-18 and the strap 12 thus hold the contact member in yielding engagement with the stop 13 and at the same time ermit the contact member to make a limitehl angular movement with respect to the support against the strain on the spring 18. The other end of the spring rests in a depression 20 in the contact member. The c ontact member is provided with a hole 21 through which a screw or other means (not shown) maybe passed to secure a flexible conductor (not shown) to the contact member. The operation of the contact finger will readily be understood by those skilled in the art. Briefly, it may be stated that in case the finger is secured to a movable art of a swit mechanism and the under gagement with a stationary cotitact, the contact member 11 will turn about its pivotal connection with the -support against the strain of the spring 18 and the contact 16 will be given a wiping action on the other contact with which it engages. It will be understood by those skilled in the art that the support 10 for the switch, member ma be stationary, and the contact (not shown which makes engagement with the I contact 16 maybe movable, as for instance in the case of a drum controller or'the like.

' One of the features of my invention is its simplicity and the cheapness of its manufacture. Thus, all of the parts with the exception of the spring maybe made of stampswitch may be very quickly assembled; as for instance, by placing the contact member 11 in position with respect to the support 10, then slipping the strap 12 over the member and the contact with the ends of the strap disposed in theaperture in the support for positioning the strap with respect to the support, and finally placing the spring 18 between the contact member and the upper end of the strap. The contact finger has a very small number of parts, and the construction makes it possible to eliminate a number of parts which have heretofore been considered necessary in contact fingers of this character.

The contact member 11 can readily be replaced in case it has become worn in service by simply removingthe spring 18, slipping out the contact member, replacing it by another, and finally replacing the spring 18.

In accordance with the provisions of the patent statutes, I have described the principle of operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereof, but I desire to have it understood that the apparatus shown is only illustrative, and that the invention can be'carried out by other means.

What I claim as new and desire to secure by Letters Patent of the' United States, is

1. A contact finger for electric switches comprising a contact member, a support for the member having one of its ends intermediate the ends oif the member one end of the member'carrying a contact and the other end adapted to cooperate with the support to form a pivot about'which the member is permitted a limited angular movement, a strap embracing the support and member intermediate the said end of the support and the said pivot, and a coiled spring interposed between the strap and the member for holding the member in engagement with the support and permitting movement of the member about the pivot, the said straphaving a projecting portion adapted to enter the support for positioning the strap with wearer respect to the support and a depressed portion which coo erates with the spring for holding the spring in position'with respect to the strap and the contact member.

2. A contact finger for electric switches comprising a contact member, a support for the member having a stop disposed intermediate the ends of the member, one end of the member carrying a contact and the other end of the member having a projection adapted to cooperate with an aperture in the support to form a pivot about which the member is permitted a limited angular movement, a coiled spring for holding the contact member and the support in yielding engagement, and a strap embracing the support, the contact member, and the spring intermediate the said stop and pivot for placing the spring under strain, the said strap having projecting ends adapted to enter an aperture in the support for positioning the strap with respect to the support and an integral depressed portion which fits in the one end of the spring for holding the spring in position with respect to the strap and the contact member.

3. A contact finger for electric switches comprising a support, a contact pivotally mounted with respect to the support, a coiled spring for holding the contact and the support in yielding engagement, and a strap embracing the support, the contact member and the spring for placing the spring under strain, the said strap consisting of a narrow strip of material having a punched in portion midway of its ends which is inserted in one end of the spring for holding the spring in position and having integral kicked up ends which substantially meet on the side of the support which is opposite to the side on which the said contact and spring are car- -ried and which are adapted to enter an aperture on the said opposite side of the support for positioning the strap with respect to the support.

In witness whereof, I have hereunto set my hand this 14th day of Dec, 1920. v

GEORGE LEDDICII. 

